Spatiotemporal dynamics of tire wear particles reveal escalating emission inequalities across China’s road network

Non-exhaust emissions are rapidly emerging as a major contributor to traffic-related particulate pollution, yet their emission patterns and impacts remain poorly constrained at large spatial scales. Here we present a nationwide, road-network-resolved assessment of tire and road wear particles (TRWP), integrating harmonized field measurements, machine-learning models, traffic activity data, and epidemiological models. China’s road network emitted 425 kt of TRWP-derived fine particulate matter (PM2.5) in 2023, nearly 80% originating from modeled vehicle-induced resuspension. These emissions and exposures exhibit spatial inequalities, concentrating health risks in densely populated economic corridors and megacities. The contribution of TRWP to PM2.5 is projected to increase 34-fold from 2011 to 2050, with tire-derived particles accounting for 67% of traffic-related PM2.5 emissions by 2050. Implementing synergistic mitigation strategies could reduce these annual emissions by 41%. Our findings highlight an urgent need to expand transport and public health strategies beyond exhaust control to include non-exhaust particle mitigation. As vehicle exhaust emissions fall, tire and road wear particles (TRWP) are becoming a major PM2.5 source. In China, road traffic emitted 425 kt of TRWP PM2.5 in 2023, concentrating risks in cities. Without action, TRWP will grow by 2050, but targeted measures could cut emissions by 41%.